U.S. Pat. Nos. 4,153,679 and 4,226,988, hereby incorporated by reference, disclose the use of paramenthane and acyclic carboxarnides as having a cooling effect on the skin and mucous membranes. These patents disclose the preparation and separation of the compounds through a three-step reaction sequence. The steps basically involve the hydrolysis of the compounds to an acid. The acid product is then reacted with thionyl chloride to form an acid chloride. The acid chloride is then reacted with an alkylamine to form carboxy amide
While this reaction is suitable for preparing the carboxamides, the process does not lend itself to the manufacture of the desired product in a simple economical process.
There is an ongoing need to provide the amides in high yield and in a simple, cost effective manner.